Monday, January 5, 2015

Bird of the Day: Sandhill Cranes amid California Gold

Gold made California a state, but the real gold, as I wrote a few weeks ago over in Geotripper, is in soil. The Great Valley is a geological oddity in the American West, an exceedingly flat landscape with abundant water resources, despite the aridity of the valley floor. Wet humid climates tend to form acidic soils deficient in plant nutrients, but the water in our valley doesn't come so much from precipitation so the nutrients don't wash away. The water comes from Sierra Nevada rivers, which wind their way across the valley floor. The valley soils are therefore some of the richest in the world. Given the snow-free climate, the growing season can last all year, depending on the crop.

Humans have known of the valley's richness for a bit more than a century and a half, but animals, and birds in particular, have known for much longer. Hundreds of thousands of years more. They've been migrating to and wintering in the valley since the plains rose above sea level a few million years ago. Agricultural and urban development have eliminated most of the original ecosystem, but a series of preserves provide refuge for millions of birds. One of my favorite bird-watching spots is an observation platform at the edge of the San Joaquin National Wildlife Refuge near the end of Beckwith Road just west of Modesto. It takes only a few extra minutes to check things out the way we did a couple of days ago. In the setting sun, the fields of cut cornstalks (grown to feed the birds) looked golden. A few dozen Sandhill Cranes (Grus candensis) were grazing among the stubs. It looked like they were sorting through gold bars.

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